WASHINGTON � Former CIA officer Valerie Plame should explain "differences" in her various accounts of how her husband was sent to the African nation of Niger in 2002 to investigate reports Iraq was trying to buy uranium there, the vice chairman of the Senate Intelligence Committee said.

Plame's differing versions have furthered "misinformation" about the origins of the case that roiled Washington beginning in July 2003, said Sen. Kit Bond, R-Mo. Plame gave those accounts to the CIA's inspector general, Senate investigators and a House committee in March.

A February 2002 CIA memo released last week as part of a study of pre-Iraq-war intelligence shows that Plame suggested her husband, former State Department official Joseph Wilson, for the Niger trip, Bond said. That "doesn't square" with Plame's March testimony in which she said an unnamed CIA colleague raised her husband's name, Bond told USA TODAY.

Here are Plame's three versions of how Wilson was sent to Niger, according to Bond:

•She told the CIA's inspector general in 2003 or 2004 that she had suggested Wilson.

•She told the House Oversight and Government Reform Committee in March that an unidentified person in Vice President Cheney's office asked a CIA colleague about the African uranium report in February 2002. A third officer, overhearing Plame and the colleague discussing this, suggested, "Well, why don't we send Joe?" Plame told the committee.

CIA officials have been unable to verify Plame's March version, Bond said. Paul Gimigliano, a CIA spokesman, said the "public record on the matter is extensive, and, at this point, I can't add anything to it."

Plame's identity as an undercover CIA operative was revealed after Wilson accused the Bush administration of ignoring his Africa findings. The disclosure of Plame's status led to a federal investigation that culminated in former White House aide Lewis "Scooter" Libby's conviction on charges of perjury and obstruction of justice.

Libby is scheduled to be sentenced next Tuesday. In court papers made public last weekend, prosecutors recommended he be sentenced to 30 to 37 months in prison.

A spokeswoman for Sen. Jay Rockefeller, chairman of the Senate Intelligence Committee, said she's not sure whether Rockefeller would support having committee investigators interview Plame. The priority for Rockefeller, D-W.Va., is finishing the committee's investigation into Iraq war intelligence, Wendy Morigi said.

Bond said he has written to the CIA for permission to re-interview Plame.

Plame has "always been very consistent that she is not the person responsible for sending Joe Wilson" to Africa, said Melanie Sloan, Plame's attorney.

Questioning Plame's truthfulness now, she said, is an attempt to draw attention from the "real wrong here � a White House that outed a covert operative and undermined national security."

Wilson, a former ambassador to Gabon, said later that he had found nothing to support the report that Iraq was trying to buy uranium for a secret nuclear program from Niger.

In July 2003, Wilson wrote a column in The New York Times accusing the Bush administration of twisting prewar intelligence by including the erroneous report in the president's State of the Union address the previous January � two months before the war began.

Days later, Plame's CIA employment was revealed by syndicated columnist Robert Novak. Plame and Wilson said the implication that she had used her CIA status to arrange her husband's Niger trip was false. The disclosure, they argued, was meant to discredit Wilson and his findings by suggesting that the trip was merely a junket.